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910Esprit

Project A/C R12 to R134 in a G car

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Thanks Dave.

 

There is no repair there and the drivers side is the same, all joined up. Which makes sense really from the bodyshell strength aspect as the A-pillars feed into the whole of the frontal area.

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post-13282-0-80407800-1406186774.jpgpost-13282-0-71951700-1406186813.jpgandy i am amazed you have no void between the top of the wing and front boot. your side repeater wiring must go down there.

you will have to make holes both sides as the line from drier and expansion valve runs through the other side. hear is a pic of the clip under the head light pod which is original as i did remove the clip to get my old pipe out . also a pic of the pipe run on the filter drier.

that is well tight to get it all in.

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Andy there is a void there. It runs all the way through from behind the washer bottle to where the repeater light is and the repeater wiring runs through it. But no path from this void into the passenger footwell.

 

I am actually surprised that Steves car is open here, because it means the passenger footwell is essentially open to the outside world because the void between the inner and outer wheelarches is open both at the front by the pod and the door hinge/repeater area.

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Not even at the top of the foot well?

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Not even at the top of the foot well?

 

Nope. I have the whole fascia etc out so I can get a good view. The footwell is all closed up. There are of course the bulkhead closing panels to the left of the heater but they blank the space between the footwell and the inside of the plenum chamber, not the inner/outer wing gap.

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BTW what on earth is that random 2N3055 transistor doing there? I have no idea what thats for and have not got round to tracing where the wiring goes.

have not seen any 3055's on my car, got the full interior out including the dash till the last bolt (rhd to lhd conversion ) btw have not seen any 2n3055 in a long time, they remind me of the 80's building RC stuff. 

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i must have had a a hole  in mine but i can't get to it at the moment as the car is on my lift so can't open the door and the cam covers are off to paint. so its a no driver at the moment.

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Andy W - I dont think its totally open, I recall there being a small closing panel with a hole for the pipe - but its much further forward.  Otherwise, I don't think the passenger would need any air con ;-)   

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Well I did the deed and drilled holes now, so thats done.

 

I came up against a problem. I decided to remove the cylinder head on the compressor and rotate it 90 degrees (also gave the opportunity to clean out the reed valves etc). Dave at Lotusbits suggested this might be a good idea, and the reason is, the body of the comp has to be mounted with the oil filler hole at the top (ish) but this leaves the ports emanating upwards. This is less than ideal because the hoses have to curve under the engine.

 

What I should have done before this is checked the availability of the gaskets for this before taking it apart. I now find there arent any in the world. 4seasons are trying to get some but not sure how long it will take. fact is, parts for these old comps are becoming rare and Steves idea of replacing the entire unit seems very sensible.

 

The ceramic shaft seals are still available from 4seasons though so I did replace this.

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Just ran the hoses today, it occurred to me the hard rubber hoses are more likely to clonk around inside the sill and front wing than the OEM braided hoses so I went down to Wickes and bought some pipe insulation and added short pieces of this to the hoses at strategic points.

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Today is the big day.  To resolve the #12 flare issue I've had to use a #12 flare and an inline reducer from #12 to #10 (for the evaporator to compressor run).   Had an enjoyable time getting that routed....  Inserted new PAG oil (1oz for new receiver and an estimate of the old oil I got out of the system)   Also added 10ml of U/V dye.  Finally connected up the new receiver/drier last, so the system is now 'gastight' (theoretically!).

 

I'll be doing the vacuum down later this morning and if all goes well the charge.   Will report back later.    

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Well there was some good news and some less good news....   Ran the vac pump for about 45 mins and it was showing 30 inches of vacuum.  So far so good.  Took Mrs M shopping and it was still reading 30 inches on return .  Excellent.  Ready to charge.  However I just ran the vac pump for another hour as it seemed a good idea.
 
Then to the charge.   Hooked up the low and high side & charged statically (without compressor running)  Got up to about 60 psi on the gauges.   Next stage was to get the compressor cycling.  This is where the problems start - Although the compressor is running when engaged, its not significantly compressing.   Can only generate around 70psi high side, with not enough reduction in low side to draw further refrigerant into the circuit    
 
Conclusions - The compressor is not working - specifically the valve plate.  Whether I damaged it. or it may explain the £15 (new) purchase price I don't know!
 
So all is not lost - Looks like the pipework is good.  I wont have wasted too much refrigerant   I just need to look for another compressor, which will be a straightforward swap next time.  In the meantime, I'll have a look inside the suspect compressor and see what's up.
 
gauge.jpg
 
compr.jpg

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I thought your £15 price was a typo!

 

Not a lot can go wrong with these unless the clutch is not engaging. 

 

I found another UK supplier http://www.apairltd.com/ who have the Sanden gasket set in stock so I have this arriving tomorrow. They also list the no 12 flare to no 10 hose fitting so looks like I didnt need to get this from the USA after all.

 

Just finished re-wiring the fans. As the parallel-flow condenser is smaller. it only covers 2 fans so I have added a second fan relay so two fans come on when the comp is engaged but all 3 come on when the otter switch closes.

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Well I'm open to suggestions  (Andy B?)   Clutch deffo engaging as revs drop as normal and gauges register 'something' is happening.   My only other hunch is that the expansion valve could be clogged and the initial charge is too low?   Can't see anything else it could be.   I'm just about to run a further check - If the pressure (High/Low) equalises almost immediately after cycling that suggests a valve problem.   If the high & low maintain a differential that suggests the Expansion (maybe!!) 

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I was waiting for this are you revving the engine say 2500 rpm. If your ex/vale is choked you would have vacuum on the suction side.

put some more gas in and set the revs to 2000 and watch the pressure. report back.

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Originally all actions were on tickover, but tried various rev ranges thereafter.   The curious thing is that the low side doesn't show any appreciable change in pressure at all when the compressor is running (it just shows the 'ambient' circa 50psi today)  (even at say 2500 rpm).  The high side needle lifts a little when running but not by much (circa +10 psi) I cant put any more gas in as it doesn't want to go in!  presumably as there is no low side vacuum being generated. 

 

However, after venting a minute (it really was negligible) amount of gas in the low side gauge/pipe to allow it to drop to zero, it maintains the differential between high and low for a significant period of time e.g. 30 minutes or more  (i.e high continues to read 50, low reads zero) - this maybe debunks my compressor valve theory, as this seems to suggest they don't leak.

 

I suspect the symtoms would be identical if the compressor wasn't running - but it definitely appears to be.  (clutch engages & revs drop)

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That would only confirm that the valves on the low side of the vavle plate are closing. It doesnt confirm the valves on the high side of the plate are closing when the pistons are on the intake stroke.

 

It can only really be a compressor problem of the exp valve is stuck wide open.

 

Is the original compressor still OK, maybe you could try it? 

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I'm hoping I had a 'eureka' moment last night.   What if the low side shreader valve is inoperative?  Symptoms - can't detect any vacuum low side, cant introduce refrigerant low side.  It may also explain the fact that the only gas low side was very small - e.g. the gas from the manifold itself perhaps?   However even with a valve inoperative you would get false positive readings as during static charging, both low & high are open and share equal pressure from the bottle until they are isolated..   Unfortunately work now gets in the way of tests....

Edited by 910Esprit

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Well a cautious whoo hoo - Low side shraeder is indeed inoperative as the coupler does not engage properly and does not depress the pin.  The system is therefore effectively empty.   Next I need to resolve the problem, which appears to be over zealous plating on the pipe coupling.  

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To resolve the #12 flare issue I've had to use a #12 flare and an inline reducer from #12 to #10 (for the evaporator to compressor run).   

 

I'm going to have to do that as well. The #12 flare to #10 hose fitting I got from the US is too long and the passengers feet will hit it. I will need to get a 90 degree #12 and a hose reducer with a short piece of #12 hose. I assume thats how you ended up?

 

Another issue is despite the advice I was given, the cylinder head cant be rotated on the compressor as its pinned. So it was a waste of time taking it off although I did get to clean out the reed valves.

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Hmmm strange - My #12 flare exits the evaporator horizontally, so I've just used a standard straight connector and then the hose routes behind the glovebox and then just follows the A post down into the sill.   Anything other than a straight comnector would be unsuitable for me.

 

Think I've fettled my low side pipe & coupler so may have another chance at charging later today.         

 

But you can rotate the entire compressor?   It has symetrical mounting points and the Sanden website gives info on acceptable mounting angles (The 'filler' plug can be upto 90degrees from vertical.) 

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The evap outlet is horizontal but its angled towards the back of the car by 45 degrees. This looks very strange with the fascia and glovebox out as the hose is kind of in mid air.
 
With the crossbeam and glovebox in, it makes a lot more sense, it is above the bottom of the box and behind it so not really exposed to being kicked.
 
Rotating the comp I was going to do anyway but the hose routing would have been much better with even more rotation.

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Steve.

If you haven't engaged the shrider  valve when charging then it stands to reason you haven't vac'd the system either.

You will have lost gas by removing the gauges so why don't you open the system at the drier and purge.

That way you know you are putting gas into the system. you can then pull your vac and see if it holds the vac to check for leaks.

this way is more environmentally friendly than gauge lines on and off. my 12 line is straight into the evap and is well out of the way. 

when you vac or purge or charge only do it through the suction side. if you don't want to purge open the system at the drier and see if you have a negative pressure to do this pull a vac on the high side and low side of the gauges and you should have vac on both open ends at the filter. put it back together and pull the vac from the suction side of the comp. good luck hope you are successful.

andy b

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The eagle has landed - note minimum temperature of 4.5 Celcius...   Well happy with that as this was only intended as a first leak detection run!    The ambient was actually 20.5 (18.6 is stored minimum for the internal thermometer).

 

It was all down to the duff Schrader connector - My advice for anyone would be to use the more expensive versions that have an adjustable 'pin depressor'.  

 

The compressor is also cycling correctly so i know the thermistor is also working.  

 

NB - The thermometer I used are currently on sale in Lidl (£3.49) - it is an internal/extermal device with a probe, so makes the real performance very easy to measure.   The UV torch came from ebay for less than £1.50 delivered - how do they do that?   The U/V dye has already paid dividends as I had a leak at the receiver/drier.   Nipped it up a little, so I'll check again in a day or so.

 

So that's it (hopefully).  Will obviously keep checking for leaks over the next few days/weeks.

 

In reality, the overall job was actually very straightforward, the only trick bits was sourcing all the parts and ordering the fittings 'blind' also the 'schrader' issue.   Probably about 10-15 hours pure labour effort  (and a significant investment in tooling).

 

If you recall, I've used a smaller compressor than standard  (5.5ci vs 8ci), so I am curious what the difference would be with the 'correct' compressor.  I'm sure it won't be colder, is it that it can deliver a larger volume of cold air?  Or maybe it doesn't need to work as hard?   Any ideas?    

 

 

temp.jpg

Edited by 910Esprit

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